Jump to

Abstract

Background/aims Pioglitazone (PIO), a thiazolidinedione (TZD), is an insulin sensitizer used to treat type 2 diabetes (T2D). TZDs are generally safe, but may be associated with fluid retention causing edema. In PROactive, patients with T2D and cardiovascular (CV) disease were randomized to PIO (starting at 15 mg titrated to max 45 mg) or PBO, along with existing glucose-lowering and CV medications. The mean follow-up was 34.5 months. Investigator-reported serious heart failure (IRSHF) was more prevalent in the PIO group vs PBO, while outcome of IRSHF was similar. Unlike other CV events IRSHF was not independently adjudicated. To verify the accuracy of IRSHF a post-hoc, blinded review was conducted by 3 independent cardiologists.

Methods The review comprised all reported HF episodes (in or out of hospital) pneumonia, deaths partly or wholly due to HF, and fatal cases where cause of death was reported as “other cardiac” or “other CV”. All non-fatal HF cases were categorized on balance of probabilities as

present;

may have been present;

unlikely. For category 1, the symptom had to be supported by evidence (echocardiography, chest x-ray) according to available HF guidelines.

Results Although adjudication dismissed some IRSHF, it confirmed a higher prevalence with PIO than PBO (5.7 vs 4.1%; see table⇓). Mortality in which HF may have been involved remained similar between treatments. Only 2 cases of pneumonia should have been reported as HF with PIO and none with PBO.

Conclusion The analysis confirms that mortality due to HF was similar between treatments, despite increased reports of IRSHF with PIO therapy.